Actually we do. The structure of language follows specific constraints and characteristics in all languages - a Meta-language. Despite, seemingly, huge gaps between many tongues the meta-language is at the root of all.There are people (very few) that can hear a new language, drop it into the meta-language structure, and understand it. Whether language emerged in one location or many - the common structure of the human brain would dictate common language structure.

I agree. I am a bit of a linguistic student myself. I recommend reading Geofry Chauser. There is a website dedicated to him, complete with lessons on middle English. I could go on and on about this, but there's a lot to learn about the development of language and the relationship that all languages have with each other.

By the way, middle English is easier if you can speak at least a little German.

I remember learning medieval poems by rote at school. There were those famous traveling minstrels like Walter von der Vogelweide. I wonder, if they were in contact with English counterparts and if they were able to understand each other.

Linguistic and the evolution of language is a fascinating, but difficult, area of study. I don't think many people fully appreciate the degree to which the language they speak influences the way they process and analysis information and ultimately structures the brain.